Modified Transition Matrix Simulations of Communication Systems

We apply appropriately enhanced transition matrix and multicanonical methods to communication systems. Our procedure not only predicts time-independent quantities such as the bit-error-probability but can also be applied to dynamic effects such as the distribution of fading times.     

Stability issues in vector electric field propagation

Demonstrates that although standard paraxial and wide-angle vector field propagation techniques lead to divergences for sufficiently small grid-point spacings and large refractive index differences, stability may be restored through either certain Pade approximates to the propagation operator or suitable boundary conditions. The authors also introduce a novel alternating directional implicit method applicable to less divergent discretizations of the vector wave equation     

A vectorial boundary element method analysis of integrated optical waveguides

In this paper, a new vectorial boundary element method is introduced and applied to the modal analysis of dielectric waveguides with piecewise homogeneous refractive indexes. The procedure, which is free of spurious modes, determines the full field distribution from the longitudinal fields at the refractive index boundaries. Singular kernels are evaluated through series solutions while the electric field discontinuity at corners is accommodated through either a grid refinement technique or a semianalytic approach. Our formalism generates propagation constants and modal field distributions for several representative refractive index profiles with far higher accuracy than standard finite-difference or finite-element procedures.     

The influence of screening on the auger coefficient of 1.3 µm InGaAsP lattice matched to InP

We demonstrate numerically that calculations of the Auger coefficient of 1.3 μm InGaAsP are appreciably affected by the assumed screening parameters, especially at low temperatures and high carrier densities. We also generalize earlier theories of Auger processes to prove that the screening length should be set to infinity in such calculations.     

Split-step finite difference analysis of rib waveguides

Presents a new rapid approach to the analysis of strongly guiding and longitudinally varying semiconductor rib waveguide structures. The technique, which is a synthesis of the beam propagation and finite difference methods is Hermitian, second-order accurate and intrinsically stable.<>     

Split-operator electric field reflection techniques

The authors have analyzed several approximations for the reflection coefficient of an electric field incident on the interface between two inhomogeneous dielectric media. While existing expressions agree with exact results in certain limits, realistic waveguides with discontinuous refractive index changes are often more accurately modeled by dividing the incoming electric field into segments coinciding with the intervals over which the interface is continuous, and subsequently superimposing the reflection from each segment.<>     

Frequency Interpolation of Jones Matrices

We estimate the frequency-dependence of the Jones matrix of an optical fiber from its values at several discrete optical frequencies and illustrate our procedures through calculations of higher order polarization-mode dispersion effects in optical fibers     

Coupling strength and influence in cleaved-coupled-cavity lasers

The coupling between the segments of a C3 laser is calculated, and threshold plots for small gap perturbations are shown to differ substantially. Cases of strong, intermediate and weak coupling are compared.     

Near-field distributions in selectively excited elliptical optical fibres

Short (1?400 m) multimode fibres were excited by a single-mode fibre. The resulting near-field intensity distributions are generally not circularly symmetric. A calculation based on ray optics shows that slightly elliptical fibres give similar distributions. This calculation assumes a central index-profile dip.